Compact package and Superior design of the Planar ServoRingrotary stages wasoptimized to minimize stage height. The low profile of the stage reducestotalsystem working height. Angular contact bearings are used to maximizeperformance withrespect to wobble, moment stiffness and friction. ULTRATHIN ServoRing stage haslarge clearcenter aperture that can be used for air or wire line feed-through orbeam delivery.